[T-cell rich B-cell lymphoma: diagnosis, differential diagnosis, and classification of two representative cases].

Two post mortem examinations from the Institute of Pathology, Albert-Ludwigs-University of Freiburg, will be presented. In both cases diagnosis of a T-cell-rich B-cell-lymphoma was first established after necropsy and evaluation of the immunohistochemical results. In the first case a peripheral T-cell-lymphoma was diagnosed after a peripheral T-cell-marker test. A liver biopsy showed suspicion of a Hodgkin-lymphoma. In the second case a biopsy of an extended retroperitoneal tumor showed a centroblastic non-Hodgkin-lymphoma 3 weeks before death. By autopsy we found in both cases a wide infiltration with small monomorphic lymphocytes. Less than 20% of the infiltrate consisted of polymorphous blasts with a wide morphologic range and prominent nucleoli. Immunohistochemistry showed the blasts to be CD20-positive, while the small monomorphic lymphocytes expressed the CD3 marker. In the first case kappa-light-chain-restriction was shown in the blasts by immunohistochemistry. Differential diagnosis difficulties, diagnostic criteria, prognosis and classification of these cases in the common non-Hodgkin-lymphoma classification will be discussed in view of the current literature.